1. Field of the Invention
This invention relates to a recording device such as a plotter or the like in which different kinds of recording pens are used in an interchangeable manner, and more particularly, to a device for changing the writing pressure by a pen holder when changing the recording pen.
2. Prior Art
Examples of various conventional recording pens used in a recording device or the like, such as a plotter, include a water-ink ball point pen, a water-ink fiber tip pen, a disposable pen, a ceramic pen, an oil-ink fiber tip pen, and so on. These pens have their own characteristics, and a proper one of them is selected depending on the purpose of use. For example, for drawing purposes, there is used the ceramic pen which can draw a line with a constant width and therefore can be easily handled. For drawing a graph, there is used the water-ink fiber tip pen which can draw a clear and colorful line.
However, when the kind of pen is changed, there are encountered problems that lines drawn on a recording paper may be blurred and that a nib of the pen may be damaged. These problems arise out of the fact that a proper writing pressure is not applied in accordance with the kind of pen. For example, a proper writing pressure depending on the kind of pen is about 50 g for the water-ink ball point pen, and about 20 g for the water-ink fiber tip pen, the oil-ink fiber tip pen and the ceramic pen. For example, when the water-ink ball point pen is selected and used, and then is exchanged by the ceramic pen, the writing pressure is too high for the ceramic pen, which results in problems such as blurred lines and damage of the pen nib.